(1) item text \(\stackrel{PLM}{\Longrightarrow }\)  text encodings. We utilize the widely used BERT model [1]} to encode the text information of items. Given an item \(i\) , we insert a special token [CLS] at the beginning of its item text \(t_i\)  (denoted by \(\lbrace w_1, \ldots , w_c\rbrace \) ), and then feed this extended text to BERT
for obtaining the text encoding of item \(i\)  as:
\({x}_i = \text{BERT}(\left[\texttt {[CLS]};w_1;\ldots ;w_c\right]),\) 
